Switching devices are generally known. Merely by way of example, reference is made to U.S. Pat. Nos. 3,745,492, 5,844,186 and WO 99/56295 A1.
In order to ensure that electrical systems are not live while work is being carried out on or in these systems, main switches and switching devices with disconnector characteristics are specified. On the one hand, these must reliably signal, either by way of a visible disconnection gap or by an indication which reliably indicates the switching state of the device, the disconnection of the system from the supply. In particular, however, they must allow blocking which reliably prevents accidental connection. Furthermore, the switching point must reliably withstand an increased voltage. Furthermore, predetermined creepage currents must not be exceeded.
Devices of this type are described, for example, in IEC 60947-2 and IEC 60947-3. These Standards are implemented in electrical devices such as disconnectors, load disconnectors, safety load disconnectors and circuit breakers with a disconnection function, and similar devices.
Electromagnetic switching devices according to the prior art as cited above satisfy these requirements.